#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include <string.h>

int main() {

    int arr[128] = { 0 };
    char str[501];

    gets(str);
    int len = strlen(str);
    for (int i = 0; i < len; i++)
    {
        arr[str[i]] = 1;
    }

    int count = 0;
    for (int i = 0; i < 128; i++)
    {
        count += arr[i];
    }
    printf("%d", count);

    return 0;
}

int majorityElement(int* nums, int numsSize) {

    int amzing = nums[0];

    int count = 0;
    for (int i = 0; i < numsSize; i++)
    {
        if (amzing == nums[i])
            count++;
        else if (count == 0)
        {
            amzing = nums[i];
            count++;
        }
        else
            count--;
    }
    return amzing;
}

int cmp(void* p1, void* p2)
{
    return *(int*)p1 - *(int*)p2;
}

int majorityElement(int* nums, int numsSize) {

    qsort(nums, numsSize, 4, cmp);
    return nums[numsSize / 2];
}

